1. Field of the Invention
The invention concerns a temperature measuring device for a regulating circuit in particular of an electrical radiant heating appliance with a heating conductor arranged beneath a glass ceramic cooking surface.
2. Discussion of the Prior Art
DE 31 00 758 A1 describes a switch device for cooking appliances with a glass ceramic plate, wherein a mechanical expansion element is disposed as a temperature sensor between the glass ceramic plate and a heating conductor. When a reference temperature is reached the heating conductor is switched off by means of a switch contact which is coupled to the expansion element, and it is switched on again with a certain hysteresis effect.
A temperature regulator for electrical cooking plates with a hydraulic temperature sensor is known from DE 28 50 389 B2.
Prior German patent application No. 195 22 748 describes a regulating device for a hot plate radiant heating arrangement. The mechanical expansion sensor which is also provided here is additionally heatable by means of an additional heating body whose output power is adjustable by means of a control member.
In all cases in the state of the art referred to, a specific sensor element is required for detecting the temperature of the cooking surface.
DE 29 36 890 C2 discloses a temperature regulation system for an electrical surface heating arrangement. A heat-sensitive element is arranged between the heating element and a temperature sensor electrode. The heating element itself is admittedly part of the temperature sensor arrangement, but in this case also additional elements, more specifically the temperature sensor electrode and the heat-sensitive element, are necessary for temperature detection purposes.